This invention involves guidance systems to aid drivers in tunnels and the like to properly navigate a predetermined path along the length of the tunnel.
Many people are uncomfortable driving through long tunnels, especially those having either poor lighting or those having unclear lane designations. The driver may veer from his/her lane and travel either into the opposite lane or into a curb or other structure on the side of the road. A similar situation also occurs with respect to other structures similar to tunnels, such as beside toll booths and other small through-passages. The drivers may be unable to determine clearance around these structures and may contact the walls or barriers. This is especially true for wider vehicles or those pulling large items, such as boats or trailers. While the vehicle itself may easily clear the structure, a small misalignment may cause the trailer to contact the toll-both barriers.
The prior art discloses a wide variety of automated driving aids, namely U.S. Pat. No. 6,163,745 to Purchase et al, U.S. Pat. No. 5,781,119 to Yamashita et al and U.S. Pat. No. 4,933,864 to Evans, Jr. et al. Each of these references discloses a method whereby a beacon or the like is placed above the road, tunnel or hallway to guide a robot or automatic driving device for a vehicle through such road, tunnel or hallway. For example, Purchase et al disclose placing fluorescent material above a mining tunnel path which reflects a certain frequency of light As the automatically driven cart detects the specific frequency of light along the path, it is able to adjust its alignment to continue along the center of the path. However, each of the apparatuses used in these inventions requires extensive detection means and computer-aided machinery to guide the driving device through the tunnel, which can be very expensive. Additionally, once the vehicle exits the road, tunnel or hallway, the device becomes inoperative with the guide device. Further, none of these references operates in conjunction with a human driver to guide them along the road.
It is therefore an object of this invention to overcome the disadvantages of the above noted devices and provide a guide system for guiding a human driver down a road or through a tunnel or the like. It is still a further object to provide a guide system that is simple in structure and requires minimal additions to existing vehicles. It is another object to provide a guide system that does not interfere with the normal driving operations of the vehicle whether inside the tunnel or the like or outside on the open road.
These and other objects of the invention are accomplished with a simple light guide system having a linear light source which provides a guiding line projected onto the road and the vehicle providing a reference for the vehicle to follow as it travels down the road, tunnel or the like. When the driver of the vehicle aligns the linear light source on a predetermined indicator on the vehicle, the vehicle is properly traveling down the center of the road lane, tunnel lane, or the like. This would be accomplished by turning the vehicle so that the vehicle moves laterally with respect to its line of travel so that the guiding line linear guiding ray coincides with the indicator. Such coincidence between the indicator and the guiding line assures that the driver is traveling down the center of the lane. The predetermined indicator is at a location on the vehicle predetermined by the driver, which can be a dot on the dashboard, windshield, or sticker placed on the vehicle, the center of the hood, the hood itself or any other item useable as a reference.
The light sources may be lasers or other devices that emit sufficiently bright light and fine light paths. A laser beam may be rotated in a circular pattern to change the single ray into a line ray or light from other light sources may be projected through slit arrays to create line rays.
For a longer tunnel, a group of light sources may be used spaced apart certain distances to provide a line ray along the entire length of the tunnel. Various guards and shields could be used to direct the light only in certain areas and block light from traveling into unwanted areas.
The line rays may also be projected from other structures where it is desired that the vehicle travel directly down the center of the pathway, such as the roof of a toll booth. As vehicles would pull into the lane beside the booth, the line ray would project onto the hood of the vehicle. Large vehicles or vehicles pulling a boat or trailer could align the line ray with an indicator of the vehicle to assure that they are traveling down the middle of the lane. This could prevent the large vehicle or its trailer from contacting a barrier or wall of the toll booth due to the vehicle being off-center in the lane.